Electrodeposition has long been known as a means to provide a refractory metal coating on various refractory metal substrates including wire. It is also well-known to deposit various metal coatings including refractory metals on refractory metal substrates from liquid suspensions which are thereafter heated to sinter the refractory metal constituents. It is also known to insulate electromagnetic wire continuously in a wire coating apparatus utilizing a vertically oriented heating chamber to produce a solid coating of substantially uniform thickness around the electromagnetic wire.